823 replies to this topic

[Potassium chlorate]

Why make your own German Black (or try to make it) when it's that difficult and you can buy it?

[spanner]

Some might try as a technical challenge. Others might because while you can buy it today, tomorrow may be a different story.

But its beyond 99% of pyros to produce anything close to 5413, IMHO.

[dr thrust]

Why make your own German Black (or try to make it) when it's that difficult and you can buy it?

i believe some people just like a challenge!, some people like rolling there own tubes, making charcoal etc, yes you can buy these things but its more satisfying if you can get over the odds and make it yourself, this is what amateur pyro is about, solving problems

[Potassium chlorate]

Some might try as a technical challenge. Others might because while you can buy it today, tomorrow may be a different story.

But its beyond 99% of pyros to produce anything close to 5413, IMHO.

I'm actually quite surprised that most pyro chemicals are available in Sweden without a permit of any kind, but the f**king EU will probably change that sooner or later. They banned 4" mortars this year and stopped selling 3" mortars as well, though they didn't tell more than that 4" mortars should be banned.

We have a Swedish word for those kind of politicians and bureaucrats: glädjedödare; "joy-killers".

But I also think it's too difficult for most people to make their own 5413. It was invented in a German professional pyrotechnician lab. It doesn't even seem 100% public knowledge how it's done, let alone the equipment that's needed.

Edited by Pyroswede, 12 January 2009 - 01:02 AM.

[Potassium chlorate]

i believe some people just like a challenge!, some people like rolling there own tubes, making charcoal etc, yes you can buy these things but its more satisfying if you can get over the odds and make it yourself, this is what amateur pyro is about, solving problems

I know. I'm getting old an lazy, though, like I said, I think German Black is very difficult to make for an amateur.

[knackers]

Isn't the whole problem with it becoming pyrophoric caused by the absence of oxygen in the milling container preventing the creation of the Al2O3 layer that would normally protect the Al (and therefore when it is eventually exposed to oxygen *all* of the exposed Al oxidises at the same time)?

I would have thought that if you could keep a small amount (21% or less) of oxygen present in the jar while milling the Al would produce it's protective layer as it is milled and you wouldn't have a problem. Isn't that why you are supposed to open the jar every few hours?

that depends on how quickley the milled product is reintroduced to the atmosphere, whenever you modify/deform Al, ( cut, bend, grind, weld ) it oxidises imediately, thus providing an oxide layer 'preventing' further oxidation, therefore if you mill aluminium in a austenetic/non ferous (even ferous for that matter ) apparatus with oxygen, as the friction produces heat and the aluminium oxidises it will become pyrophoric.
so therefore it has to be milled inert then reintroduced gradually, otherwise with an all might rush of oxygen it will become pyrophoric

i may also add the difficulty of obtaining a suitable valved non ferous mill jar would be out of reach for the everyday pyrotechnist as most mill jars are rubber or plastic, therefore drawing the conclusion, making your own dark pyro Al is not impossible but highly improbable,,

also......... 21 % oxygen is what you would be opening your jar to....... its what we live in..... atmospheric level

[knackers]

i believe some people just like a challenge!, some people like rolling there own tubes, making charcoal etc, yes you can buy these things but its more satisfying if you can get over the odds and make it yourself, this is what amateur pyro is about, solving problems

i agree in your logic entirely, i could catergorise my self as a little somewhat lazy, but it takes a good woman to give me more pleasure than working on a project and arriving at the cresendo of ,, YES you little ripper , " I DID IT" and it works

[mike_au]

that depends on how quickley the milled product is reintroduced to the atmosphere, whenever you modify/deform Al, ( cut, bend, grind, weld ) it oxidises imediately, thus providing an oxide layer 'preventing' further oxidation, therefore if you mill aluminium in a austenetic/non ferous (even ferous for that matter ) apparatus with oxygen, as the friction produces heat and the aluminium oxidises it will become pyrophoric.
so therefore it has to be milled inert then reintroduced gradually, otherwise with an all might rush of oxygen it will become pyrophoric

i may also add the difficulty of obtaining a suitable valved non ferous mill jar would be out of reach for the everyday pyrotechnist as most mill jars are rubber or plastic, therefore drawing the conclusion, making your own dark pyro Al is not impossible but highly improbable,,

also......... 21 % oxygen is what you would be opening your jar to....... its what we live in..... atmospheric level

I realise 21% is atmospheric levels, and that is exactly my point. If I take a hand file to an Al block and grind it all down into powder it forms that oxide layer as new surface is exposed. At no point is it pyrophoric because the amount that is being oxidised at any give moment is very small.

The inert atmosphere inside the jar isn't the solution to the problem, it is the cause of it. If atmospheric levels of O2 could be maintained within the jar during milling then the Al would form the protective layer gradually over the hours or days that it is being milled, rather than instantly when the jar is opened.

[knackers]

I realise 21% is atmospheric levels, and that is exactly my point. If I take a hand file to an Al block and grind it all down into powder it forms that oxide layer as new surface is exposed. At no point is it pyrophoric because the amount that is being oxidised at any give moment is very small.

The inert atmosphere inside the jar isn't the solution to the problem, it is the cause of it. If atmospheric levels of O2 could be maintained within the jar during milling then the Al would form the protective layer gradually over the hours or days that it is being milled, rather than instantly when the jar is opened.

i hear what you are saying, but disagree' its aparent if not obvious you can't open the jar in an instant,,, some things take time, as 02 is slowly introduced it oxidises, similar principles occur with high volume high pressure oxygen........ you can't just open the valve fully or it will blow the crap out of whatever is at the end of the line, or the line itself " you have to slowly equalise the pressure,, " in this case the oxidation"
you also don't get dark pyro Al by just milling Al, it also contains lamp black, ( friction heat, (x) micron AL, lamp black and oxygen = Trouble )

it is also such, milling other metals such as Mg is also milled in the same way ( inert ) because of the same reasons. You are using a metal drum with metal media grinding a volatile metal, the heat generated is great and NO oxygen should be present.

Edit :- i will also add, if i was going to do it i wouldn't just put it on and leave it for a week or whatever, i would be bleeding/oxidising it every day and opening to have a look and see how its going, ( gas isn't an issue as i always have a G size bottle of argon in the shed, compliments of work ) and if you have a screw type jar or cam lock type,,, ( valve less ) you will have no control over the oxidation process

Edited by phill 63, 13 January 2009 - 07:35 AM.

[mike_au]

friction heat, (x) micron AL, lamp black and oxygen = Trouble

OK, I guess that makes sense although I am a little surprised that it would be a problem.

I guess I am basing that off my experience milling bp at home, once you start looking at larger volumes and metals I suppose things change a bit.

[Potassium chlorate]

I tried 1.5 grams of my "new" flash; 1 gram KClO4, 0.4 grams Mg and 0.1 gram of Sb2S3. Not a real report but a very bright flame and a lot of nice smoke.

[spanner]

Youtube video of three different flash comps: http://uk.youtube.co...h?v=whdt46SE5O0

[Potassium chlorate]

The commercial stuff really sucks.

[spanner]

I tend to believe the video, at least the Indian dark vs. 5413. That's almost identical to my own testing.

[knackers]

i don't understand what is meant by commercial flash powder ?

we can't buy any fireworks where i live but i didn't think you could buy, say a kilogram of flash powder any where, is it what profesional pyrotechnists put in their reports/breaks, ?

Edit :- what ever it is it looks perhaps under oxidised,, and i would say its crap,,, my BP is as quick as that,

Edited by phill 63, 14 January 2009 - 08:29 AM.